Electric precipitators



March 14, 1961 Filed March 20, 1956 J. COOLIDGE, JR., ET AL 2,974,747

ELECTRIC PRECIPITATORS 2 Sheets-Sheet 1 IRE/6721107159 \fo/uz, Z (002146, J".

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March 14, 961 J. E. COOLIDGE, JR., ETAL 2,974,747

ELECTRIC PRECIPITATORS 2 Sheets-Sheet 2 Filed March 20, 1956 fur/672212715': Jim Z 00121 6596, Jr.

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U d W8 Pa Q" ELECTRIC PRECIPITATORS John E. Coolidge, In, ArlingtonHeights, 111., and Lincoln T. Work, Maplewood, NJ., assignors toBorg-Warner Corporation, a corporation of Illinois Filed Mar. 20, 1956,Ser. No. 572,662

2 Claims. (Cl. 183-43) This invention relates to means for separatinggases and particles from the atmosphere and more particularly to a gasmask adapted for removing noxious gases and also poisonous particlesfrom air.

In the past gas masks using canisters filled with charcoal or otheradsorbing means have been used to permit the wearer to operate in anatmosphere containing noxious gases. It is now contemplated that atomicbomb explosions may also leave dispersed in the atmosphere certainradioactive particles which would be injurious if inhaled. Theseradioactive particles may be small enough to pass through ordinary gasmask canisters.

One of the principal problems in using the usual gas mask having acanister containing loose granules ofcharcoal is the fact that thepressure drop through the necessary volume of small charcoal granules issuch as to make breathing difficult and the wearing of the maskuncomfortable.

It is accordingly an object of this invention to provide a novel aircleaning means especially adapted for use in a gas mask canister whichhas a very low pressure drop and which will adsorb noxious gases andalso will precipitate and collect particles from the air passing throughthe cleaner. 7

Another object of the present invention is to provide an air cleaningapparatus in which gas is adsorbed on spaced plates which also act aselectrical collecting plates for particles.

Still another object is to provide a gas mask canister that will collectboth gases. and particles and yet which is small and light in weight sothat it can be carried on the person. 1

Other objects are to provide a gas mask canister which is relativelyinexpensive, simple to-assemble and more comfortable to wear thanpresently known types. 7

Among still other objects of this invention is to provide a means forsupporting activated charcoal in spaced parallel plates whereby it isuseful to adsorb gases and also may be used as the collector plates ofan electrical precipitator. The above and further objects and novelfeatures of the invention will more fully appear from the followingdetailed description when taken in connection with the accompanyingdrawing. It will be understood however that the description and drawingare of preferred embodiments of the invention but that the invention isto be limited only by the appended claims. In the drawing: I

Fig. 1 is aiside elevational view partly in cross-section of a gas maskcanister employing the present invention, the section'being taken onthe'line 1-1 of Fig. 2;

I Fig. 2 is a side elevational view partly in cross-section with thesection taken on the line 22 of Fig. 1;

Fig. 3 is an elevational view of enact the canister plates of thecanister shown in Fig. 1;.

.screen members.

2,974,747 Patented Mar. 14,

Fig. 4 is an elevational view of a screen from the canister shown inFig. 1; a

Fig. 5 is an elevational view partly in cross-section of a modified formof canister employing the present inventlon;

Fig. 6 is an elevational view of a gas mask showing the canister inplace;

Fig. 7 is a schematic view of one form of' power pack adapted to be usedwith the present-invention; and

Fig. 8 is a schematic view of a second form of power pack also adaptedto be used with the present invention.

In the accompanying drawing the present invention is illustrated, by wayof example, in the form of a canister for a gas mask which may replacethe ordinary canister used with well-known types of face pieces to forma gas masks; but it will be apparent that the novel means employed forseparating particles from the air and for also adsorbing gases will beuseful in other types of apparatus for cleaning air other than gasmasks.

One form of novel apparatus embodying the invention is illustrated inFigs. 1 through 4 inclusive and comprises a light compact canister for agas mask which may be connected to a face piece as shown in Fig. 6. Thecanister comprises a metal or plastic container 11 which houses theelectrical precipitator. The container 11 comvprises a front 12, a back13, two ends 14 and 15, a top 1'6 and a bottom 17. Secured to the insideof the front 12 of the container is a slotted plate 18 of insulatingmaterial and a similar slotted plate 19 is secured to the back 13 of thecontainer. Supported in the slots in the plates 18 and 19 are aplurality of parallel screen members 20 which are provided with smallholes to prevent large particles of matter from passing through saidInterleaved between the screen members are a plurality of chargedcollector plates 21 and 22. Plates 21 are charged with one polarity andplates 22 are charged with the opposite polarity by means to bedescribed later. The collector plates 21 and 22 comprise a metalsupporting plate which is preferably constructed of aluminum because ofits light weight. Secured to the top and bottom of the metal supportingplate 21, 22 is a layer of adsorbing material 24. It is preferred thatthis adsorbing material be activated charcoal which is secured to thetop and bottom of the supporting plate 23 bymeans of an adhesive. Wehave found that charcoal granules of the order of 6 to 14 mesh fixed tothe metal plates provide a satisfactory adsorbing surface. Othersatisfactory structures include solid plates of charcoal supported onthe metal supporting members or a self-supporting plate of charcoal maybe used as acollector plate. Each of the collector plates 21 isgenerally rectangular in shape with two cars 25 and 26 projecting fromone side. As is shown in Fig. 2, when the plates are assembled alternateplates are reversed in direction so that a tortuous air path is formedwhereby the air passes under one side of the plate around the end of theBelow the collector section are suspended a plurality ofcharging wires29. A power pack which is not shown in Fig. 1 but may be either of thetypes shown schematically in Fig. 7 or 8 is positioned in the spacealongside the collector section. The power pack is connected to theribbons 27 and 28 and charging wires 29.

Air passing through the" apparatus enters in inlet 31 in the bottom ofthe container 11 and passes over the charging wires 29 which ionizeparticles entrained in the air. The ionized air then passes (as shownbythe arrow) along the bottom surface of collector plate 21 around the endthereof and then back along the top surface around the end of the nextplate continuing this back and forth motion through the entire canister.As the air passes over the canister plates certain gases will beadsorbed on the surface of the charcoal to which said gases are exposed.Since the collector plates 21 and 22 are charged, entrained particleswhich are also charged as they pass through the charging section areattracted to oppositely charged plates. Therefore, it will be seen thateach collector plate 21 or 22 has a twofold purpose, namely, to adsorbcertain gases and also to precipitate particles out of the air passingthrough the canister. The screen members 20 are provided principally tocollect particles of carbon which may be dislodged from the collectorplates 21 and 22 and they will also collect large particles which may beentrained in the air.

The collector plates 21 and 22 are spaced about A; of an inch apart sothat a path of considerable volume is provided for air to pass throughthe canister and the pressure drop from inlet to outlet may be held to aminimum. With plate spacing in certain models of our canisters thepressure drop has been held to /2" of water. This compares with astandard gas mask canister containing particles of charcoal looselyarranged therein which has a pressure drop of 5" of water at maximumflow.

In Fig. 5 an alternative device embodying the present invention isshown. This comprises a gas mask canister generally cylindrical in shapeand having an inlet 41 and an outlet 42 which is adapted to be attachedto a face piece 43 as shown in Fig. 6. In the inlet 41 is mounted ascreen 44 which collects large particles from the air entering thecanister. Supported in the center of the canister and running throughoutits length is a metal rod 45 which has on its lower end a charging wire46. Supported on and electrically connected to the rod 45 are collectorplates 47 which are generally annular in shape and comprise a metalsupporting plate 48 having adhered to its top and bottom a layer ofactivated charcoal 48'. It will be noted that the collector plates 47are smaller in diameter than the wall of the canister 40 so that thespace 49 is provided between the end of the plate and the canister wall.Alternating with collector plates 47 are collector plates 50 which aresecured to and electrically connected to the wall 51 of the canister 40.The collector plates 50 are also annular in shape and comprise metalsupporting plates 52 with layers of activated charcoal 53 thereon. Thecollector plates 50 are provided with an opening in the center which islarger than the rod 45 so that a space 54 is provided between the innerperiphery of the collector plates 50 and the rod 45. Between each pairof collector plates is positioned a corrugated plastic spacer 55 whichserves to help maintain the spacing of the plates and also to preventcharcoal particles from falling off said plates. A perforated plate 56supports the lowest plastic spacer.

The precipitator disclosed in Fig. 5 functions in a similar manner tothat shown in Figs. 1 and 2. Particles in the air passing through inlet41 are charged by a charging wire 46. The air with the entrained chargedparticles then passes in a tortuous path around the ends of the smallerplates and through the center opening of the larger plates. The air andthe entrained particles are exposed to the charge on the collectorplates 47 and 50 so that the particles are attracted to the charged 4 Pat an ases her i a e a s on t a coa surfaces 53 of said plates. Sincethe charcoal is electrically conductive it is also contemplated that theplates could be made of solid pieces of charcoal rather than of metalplates supporting charcoal. The cleansed air passes from the canisterthrough outlet 42 and into the face piece 43 where it may be breathed bythe wearer.

It is contemplated that a power pack for the precipitator shown in Fig.5 will be carried in a separate con tainer. Suitable connections will beprovided between the power pack and the charging wire 46 whichconnections would also be to the center rod 45 thereby charging allplates 47 attached to it. The other line from the power pack would beattached to the grounded casing thereby grounding the alternate plateswhich are attached to it.

The power pack shown in Fig. 7 comprises a switch 60, a mechanicalvibrator 61 which may be spring operated, a high voltage transformer 62,a selenium rectifier 63 and a filter condenser 64, and a battery 65.This power pack will produce approximately 2,000 to 3,000 volts. Sincethe output is only of the order of two microamperes there is no dangerof shock to the wearer.

The power pack shown in Fig. 8 contemplates the use of transistors inorder that it may be compact and light in weight. As shown the circuitcomprises a point contact transistor 70, a junction power transistor 71,a high voltage transformer 72, a selenium rectifier 73, batteries 74,feed back condenser 75, and a coupling condenser 76. Either of the abovementioned power packs may be used with the precipitators that have beendescribed.

It will be seen that by the use of precipitator collector plates coveredwith an adsorber such as activated carbon, we have provided a gascleaning apparatus which will adsorb certain undesirable gases from airand also precipitate from the atmosphere entrained particles ofmaterial. Through the use of these combination collector plates thecleansing apparatus has been made small and compact and suitable forcarrying on the person such as for gas mask use. Although one embodimentof the invention has been described as a gas mask canister it should beunderstood that the invention is susceptible of other uses such as ingas cleansing apparatus for industry.

Having described various embodiments of our invention, it will berealized that changes in the shape, arrangement and construction of thevarious features of the structures may be made without departing fromthe spirit nad scope of our invention, that the description and drawingare to be construed as illustrative only and the invention should belimited only by the appended claims.

What is claimed is:

1. A gas mask canister comprising a housing, an inlet for contaminatedair; an outlet for purified air; a longitudinal conducting memberpositioned centrally of said housing; a plurality of first collectorplates connected to and supported at spaced intervals on saidlongitudinal member and extending toward the sides of said housing withan opening between each plate and the side of the housing to provide anair path; and a plurality of second collector plates interleaved betweensaid first collector plates connected to and supported at spacedintervals on said housing and provided with openings surrounding saidlongitudinal member to provide an air path, said collector plates havinggas adsorbing surfaces, all of said first collector plates adapted to beconnected to one pole of a source of power and all of said secondcollector plates being adapted to be connected to the other pole of asaid source of power.

2. A gas mask canister is described in claim 1 wherein the gas adsorbingsurface of the collector plates is activated charcoal.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Strong Dec. 16, 1919 Thompson Mar. 5, 19355 Wilhelm Apr. 21, 1936 Gates Feb. 1, 1938 Jacob Aug. 7, 1945 Carpenteret a1; Nov. 18,1947 Richardson 'Dec. 14, 1954 6 FOREIGN PATENTS GermanyJune 5, 1905 France Oct. 22, 1934 France Aug. 22, 1938 France Mar. 4,1953

